Thermal and/or thermal-acoustical shields are used in a wide variety of applications, among which are shielding in space crafts, automobiles, home appliances, electronic components, industrial engines, boiler plants and the like, and are commonly referred to as heat shields, acoustical panels, thermal barriers, vibrational barriers, acoustical barriers, insulating shields, and the like. As used herein, such terms are considered interchangeable. Such shields may be used, for example, between an object to be protected, e.g., thermally shielded, for example, the outer dash of an automobile, and a high temperature exhaust component such as a catalytic converter or manifold. Additionally, such shields may be designed to provide acoustical shielding and/or vibration isolation.
Known heat shields are often designed for use in vehicles such as automobiles and, as such, are typically subjected/exposed to the harsh under hood environment of vehicles. In order to be effective, heat shields are utilized in those areas that are typically exposed to a variety of liquids, such as engine oil, brake fluid, transmission fluid, antifreeze, and the like, and those areas are subjected to high and low temperatures. While some heat shields can be made of thermoplastics, because exhaust gas temperatures in an internal combustion engine approach around 1050° C., heat shields are oftentimes made of heat resistant materials such as ceramic, which are heavy. In addition, these shields are oftentimes mounted under the vehicle body, facilitated with the use of threaded rods and/or fasteners. The bodies of such heat shields are often provided with circular openings for receiving the threaded rods and/or fasteners. Therefore, during installation of such shields, an installer is often tasked with using both hands to hold the heat shield in place, and in some situations, more than one installer is required for proper placement and mounting/installation of the heat shield. This type of installation, typically occurring on, for instance, an automotive assembly line, is often costly because of the number of bolts required, as well as the time and labor needed to affix these fasteners. If more than one assembly worker is required to install a single heat shield, the cost can be high, and in the cases where heat shields are being installed in multiple vehicles, it is particularly time-consuming and cumbersome.
FIG. 1 depicts a prior art cooperating means 8a formed in a heat shield (not shown) for mounting the heat shield to, for instance, threaded rods extending from a vehicle, which fails to provide sufficient retention strength. The cooperating means 8a has three slots 11a, 12a, 13a shaped to form a sideways capitalized “T”. The three slots 11a, 12a, 13a each radiate from a central passageway/recess 14a. One slot 11a is separated by another slot 12a by 180°, while slot 13a is separated from each of slots 11a and 12a by 90° angles. The cooperating means 8a includes two retention tabs 20a, 22a formed between the two slots separated by the 90° angles. A disadvantage of this cooperating means 8a is that if a threaded rod is inserted therein, and put under stress, the threaded rod will tend to press/push (or have an affinity to) against the two retention tabs 20a, 22a. The two tabs 20a, 22a are oftentimes insufficient to retain the threaded rod and tend to bend substantially, and in some circumstances break off completely, which leads to the untimely and unwanted withdrawal/removal of any such threaded rod inserted therein. As a result, the cooperating means 8A is unable to provide sufficient retention of the heat shield, and the heat shield will become dislodged.
FIG. 2 is a stylized drawing of another prior art device in which cooperating means 8a is formed in a heat shield (not shown). The cooperating means 8a has four slots 40a, 41a, 42a, 43a radiating from a central passageway/recess 44a. As shown, the diameter of the central passageway/recess 44a appears to be approximately twice the size of the length of each of the slots 40a, 41a, 42a, 43a. Each slot 40a, 41a, 42a, 43a is equidistantly separated from an adjacent slot by a 90° angle, with a tab 47a, 48a, 49a, 50a being positioned between adjacent slots. For example, slot 40a is separated from slots 41a on one side and 42a on the opposite side by a 90° angle, with tab 47a being positioned between slots 41a and 40a, and tab 50a being positioned between slots 40a and 42a. As shown, the size of each tab 47a, 48a, 49a, 50a is small relative to the size of the central passageway/recess 44a, which is a function of the short length of each slot 40a, 41a, 42a, 43a. A disadvantage with this arrangement is that the overall area of each tab 47a, 48a, 49a, 50a is quite small, therefore, the cooperating means 8a may be unable to provide sufficient retention. Failure of even one of the tabs 47a, 48a, 49a, 50a to perform properly would likely result in failure of the cooperating means 8a altogether. Moreover, in situations where the cooperating means 8a is being used for permanent retention, the heat shield may become easily dislodged, resulting in irreparable and/or costly damage to the heat shield.
Various techniques have been employed for designing and/or forming heat shields that help to ease the process of aligning, mounting and/or attaching heat shields in a desired position. One such technique involves the use of a clip-snap combination, including clips and/or spring clips, which enable the heat shield to be aligned and/or inserted into place to facilitate attachment of the heat shield in the desired position. However, these snap-clip combinations also require the use of additional fastening devices, such as fasteners that can increase installation and/or maintenance costs. In addition, the use of these clips tends to be cumbersome for installers, because the clips retain the heat shield in a manner that often restricts movement in a unidirectional movement only, thereby making efforts to reposition the heat shield difficult.
Another technique employs the use of retention tabs, which clamp or hold the heat shield in place. A disadvantage with this technique is that it requires other attachment features, such as spring arms and snap-lock connectors, in order to be effective. In addition it also restricts movement that is often needed to reposition the heat shield to a desired location.
Other techniques involve using screw connections, where screws are placed in recesses placed on the lateral edges of a heat shield body. A common disadvantage with this assembly is that is poses a handling problem for installers. When installing a heat shield with two or more screws, additional fixing means, such as bonding or adhesive tape is required to help hold the heat shield in the desired position. In addition, overhead installation is often challenging because the screws often tilt due to the use of bonding or adhesive tape, and cannot be threaded into the recesses provided for receiving said screws.
The aforementioned solutions are costly, and do not facilitate efficient installation.
In view of the disadvantages associated with currently available methods and devices for heat shield retention, there is a need for a device that, with one installer and/or with a single hand, temporarily retains and/or holds a heat shield in place prior to permanent installation in a manner that simplifies and reduces costs associated with production, installation, maintenance and/or removal of heat shield assemblies.